Well boring apparatus



- March 13, 1951 Filed Oct. 13, 1947 A. W. KAMMERER WELL BORING APPARATUS 2 Sheets-Sheet 1 I N V EN TOR. 4m W. 1 4070701 March 13, 1951 w. KAMMERER 2,545,033

WELL BORING APPARATUS Filed Oct. 13, 1947 2 Sheets-Sheet 2 INVENTOR. 4m V14 am/var Patented Mar. 13, 1951 UNITED STATES PATENT OFFICE WELL BORING ABPABATUS Atelier -Kamm n, Fu er on. Qa

Application October 13, 1947, Serial No. 779,591

T is n enti re ates o ell; boring a a tus, and more particularly to rotary drill bits of the xpansible type for dri in r rea in ho es below well casin s reater diameter than the inside diameter of easing through which the bits are capab of possine- T Thi n en o s e continua n-impar o my applications for Rotary Drill Bits, Serial No. sense filed. J e 6 119% ne Paten o, 2, 669%, an Extens ble R ta y Dr ll B s, erial N 86 8 6: fil y .29, 19

I he dev ce d sclosed th a oreme t n app i at ns, cutt r means are exp n e O li wardlv and a e held outwa dl b a s ab l ok device, which prevents their inadvertent retrace. tion and forestalls the drilling of an undersized hole- An ob ec o the i t n e tion is t pr vid for imo oved oop rat n between t e cu t means of n e t ns bl d l bit d e main bit body, the cutter means being guided in better fashion in its lateral movement between retracted and expanded positions. t A further object of the invention is to provide an expansible rotary drilling bit whose cutters ar he in their ex and d p i n by a dev e capable of automaticall a ign n t l w h p et to. th c tte s bu ho e re ative o y mo ement w h respec t th cu s i limi ed by u din m a s provided on t e main ody of the tool itself- More s ecif ally, th lockin device is capable of holding the cutter means in their outward expanded position without trans-. mitting dfilling torque thereto.

Another object of the invention resi es in the provision of an expansible rotary drill bit, in which alignment and registry of the relatively movable parts is assured. to obtain better opera,- tion of the bit and enhancement of its useful life.

The invention has other ob ects which will be? come apparent from a consideration'of the em,- bodiment shown in the drawings accompanying and constituting part of the present specification. This form will now be described in detail to illustrate the general principles of the invention, but it is to be understood that such detailed de: scription is not to'be taken in a limited sense, si c th sc p oi th invention is best defined by th ap nd d claims.

- Ref rrin t h draw n Fi 1 is a i e' l a ioh o on form of on se ib drin bit embodyi he inventi n- 2 s a on itu ina section hro h t drill b t on a a ged stale, ith t e part h wn in t a ed posi n t r ena lin the b to be lowered h e-eh he w ll here- I ig, 3 is a view simi o Fig.- .2 w-ith he orts sed n expa ded pos tion,

i 4 is a cr ss=s etion taken along the line 474 on Fig. 2,

1. Cl ims! 25 6) Pie 5 i a hoesec ion aken along the line 5 -5 on Fi 3- I F 6 is a ar ial lo tudinal secti n tak n along the line 6+=6 on Fig, 3.

Fig, '7 is a partial side elevation of the bit illust o t d .Fiel b t sent d n enlar ed s ale t r ourses o cl ri y- Fla 8 i a oross se ion ta en l n the line 8:8 on Fig. 2.

s sh w in h dr w ines v the ste ib ro a y dri l bit A is a ached to a r n of drill p B b mean of whi h it is ow red thr u a Well cos ne C i t e el ore to a o nt low e ea n sh e D at hi h en gem nt oi t e re h l is t om -enoe, The r ll b t r ra ly he a pi o i ts lo er h o e t rin the t n a h that ma ha e alr ady bee W d ate ial 8.-

lled or f r d i lin he ntral por io f new h th ab en e o ree ist n h e- The m n p r on of th h is ca ab e of eme in the bor hole b producin and a in u n a lorm ti sho lder E, a h i af oeser d,

The up e en of the bit con sts o a r i mand e H Who e uooe p n i hr eie connected to a sub l3.'forrning the lower end of the dr l o o st n B- lhis; an r n l des 1131 h l r dr l. te me er l4 slida y ih d to e ain bod '5 the hit A d scl ed in th d a in s F e- D h i r Me f the l v is hexa o a n s -h and s tele cop a rec i ed in a com ani n xa on l socket I So within the body. The mandrel M has a m te ra o on it d n mo em n wi h the body, t nward mo ement e n e e mi by engagement of an external shoulder IE on the kelly with a retainer ring I! suitably secured to th upp e of the bod It, a by he use f T e dy I5 has a p urality o e te a m un ed on i m ris ng oo ed cot su po ne embers Hi, It pi ota v carri d b tween bifurcated body arms 2'0, 20 on pivot or hinge pins 2 l, 2| suitably secured to the arms, as by welding material 22. The arms define the sides of a transverse-slot extending through the body, in which the supporting members !9 are mounted. Each cutter supnorting member consists of a depending leg 23 having a bearing supnorting pin 24 inclined inwardly and downwardly and on which is rotatably mounted a roller side cutter Anti-friction roller and ballebearing elements 26, 21 are preferably placed between each cutter 25 and bearing pin 2.4, the roller bearings 2d transmitting radial thrusts. and the ball heal":- nes. 21 both radial and xial thr s Each cutter su po in member 19 also i elu es. a u vtesdl xtendin aim it a ain hich elastic expander 3! bee i w p n e is in the ter o a compr ssed o p g received with n :ie eiher p cket 32 th bol -v 5, exerting its force against the arm 30 and tending to swing it inwardly and thus urge the cutter 25 on the other side of the fulcrum pin 2| in an outward direction. The extent of this outward movement is limited by engagement of stop shoulders 33, 33 on opposite sides of the cutter supporting member |9 with cooperable body stop shoulders 34, 34.

After each cutter 25 has been expanded outwardly by its cooperable expander spring 3| to the maximum extent, it can be locked in this position by a tubular member 35 of the mandrel H, which is piloted in the kelly M and is provided with a lock portion 41. The latter is movable from an upper position in transverse alignment with inner supporting member recesses 36, permitting retraction of the cutters, to a lower position opposite lugs 31 formed on and projecting inwardly from the supporting member legs 23, preventing retraction of the cutters 25.

The tubular member 35 is connected in swivel fashion to the kelly l4 to permit relative arcuate or rotary movement therebetween. However, the kelly and tubular member are movable together for longitudinal movement in both directions. This is accomplished by providing a stop shoulder 39 on the tubular member, received within a lower socket |4b in the kelly and abutting a companion shoulder Me in the kelly at the upper end of the socket. The tubular member 35 has an upper portion 35a extending from the shoulder 39 freely through the central bore |4d of the kelly, with the upper terminus of the upper member 35a received within an enlarged recess He in the kelly or mandrel pin l2 where a nut 35b is threaded on the terminal portion, bearing against the base |4f of the upper pin recess Me.

The arrangement between the tubular member 35 and kelly 4 is such that downward movement is transmitted from the kelly to the tubular memher through the abutting shoulders Me. 39, while upward movement is transmitted to the tubular member through engagement of the recess shoulder l4 with the nut 35?). However, the nut 35b does not serve to clamp the tubular member 35 to the kelly 4, but allows relative rotary movement therebetween.

The mandrel I! is normally held in its upper position with respect to the main body l5 of the bit and the supporting members l9 by a helical retractor spring 38 encircling the tubular member 35, with its upper end engaging the mandrel shoulder 39 and its lower end engaging a spring seat 40 at the lower end of the hexagonal body socket l5a, the spring seat serving as an upper bearing guide for the tubular mandrel member 35. member 35 is movable downwardly to engage the cutter legs 23 and resist their inward movement to retracted position during the reaming or cutting operation.

Circulating fluid can pass downwardly through the string of drill pipe D and through the tubular mandrel H for ejection from its lower discharge nozzle 35c and onto the cutters 25, to cleanse them of cuttings and flush the latter from the drilling area to the top of the well bore. This circulating fluid is also available to unlock the cutter supporting members |9, in the event they are first held positively in retracted positions by a locking device, described below.

A positive lock may be provided by securing a hook 42 to the inner portion of each cutter supporting member and inserting the ends 43 of these hooks in holes 44 in a strip 45 extending across As described below, the tubular mandrel the outlet 350 of the mandrel. The cutting tool A, after being lowered in retracted position to the point at which the reaming operation is to begin, may be released for operation by starting the pumps at the surface of the well bore, which will force fluid down through the drill string D and mandrel H for impinging upon the latch strip 45, blowing or forcing it off the hook ends 43, and permitting the spring expanders 3| to shift the supporting arms 30 inwardly and the cutters 25 outwardly against the formation.

In the operation of the device, the tool A is mounted on the lower end of the drill string B, with its parts held in retracted position by the latch strip 45, as shown in Fig. 2. In this position of operation, the compressed retractor spring 38 holds the mandrel H and kelly l4 in an upward position with respect to. the body l5, as determined by engagement of the kelly shoulder 6 with the body retainer ring With the mandrel in this position, the lock portion 41 is elevated above the lugs 31 on the cutter supporting members |9, being received within the inner recesses 36 in the supporting members, which permits the latter to be held inwardly against the action of the expander springs 3|. The tool is lowered through the well casing C, and upon reaching the position in the well bore below the casing shoe D at which the drilling operation is to begin, the pumps are started at the surface of the well bore, and fluid impinged on the latch strip 45, forcing it hydraulically off the ends 43 of the hooks 42 and releasing the cutter supporting members H! for outward expansion under the influence of the springs 3|.

The drill string B is then rotated to rotate the main bit body l4 through the splined kelly and body connection l4a, I511, the expander springs 3| forcing the arms 33 inwardly and the cutters 25 outwardly against the formation. Rotation is continued without moving the drill string B longitudinally until the side cutters 25 enlarge the diameter of the hole to the maximum extent as determined by the eventual abutting of the supporting member stop shoulders 33 with the companion body stop shoulders 34. Thereafter, the drill string is lowered to cause the formation shoulder E, produced in the well bore by the cutters 25 under the action of the expander springs 3| and rotation of the tool, to support the cutter members 25, I9 and body l5 and prevent their downward movement.

Since the body |5 cannot move downwardly, drilling weight imposed on the drilling string B shifts its connected mandrel downwardly within the body I5 against the action of the retractor spring 38 until the lower end 48 of the kelly |4 engages the upper spring seat and guide 40 (see Fig. 3). This downward movement also shifts the tubular member 35 downwardly because of the abutting between the kelly and tubular member shoulders, I40, 39, to position the mandrel or tubular member lock portion 41 opposite and in alignment with the lugs 31 on the inner portions of the cutter supporting members l9, providing a positive look by preventing inward movement of the cutters. So long as down weight is imposed on the drill string B, and the cutters 25 rest on the formation shoulder E, the cutters are'prevented from moving inwardly by engagement of their lugs 31 with the mandrel lock portion 41. It is also to be noted that further outward movement of the cutters beyond the predetermined maximum diameter is prevented by contact between the supporting member shoulders 33 and the body shoulders '3,- through which the drilling weight is transmitted to the. roller cutters 25, thus relieving the hinge pins 2| of this load.

Drilling is continued by rotating the drill bit and imposing the proper drilling weight on the cutters, to cause their removal of the formation material and reaming of the hole in a downward direction for the desired extent or length. When the drill bit is to be retracted and removed to the top of the well bore, all that need be done is elevate the drill string B, which moves the side cutters 25 above the formation shoulder E and permits the retractor spring 38 to press downwardly on the body is and move it, together with the cutter supporting members l9, downwardly with respect to the mandrel H. This action repositions the mandrel lock portion 41 opposite the supporting member recesses 3.5 and above their lugs 31, because of the engagement between the pin recess shoulder Mf' and tubular member nut 35b, permitting inward swinging of the cutters 25 and their supporting members [9 when the tool passes back into the casing C upon elevation of the drill string. Cutters 25 and their supporting members i9 will ride the wall of the casing C during elevation of the string until the tool is removed from the top of the well bore.

Pads in the form of longitudinal drag-ream-- ing blades 46 can be formed at the lower. outer surfaces of the cutter supporting members I}, which will ride the inner wall of the casing and prevent the cutter teeth from hanging up in the casing coupling spaces while the tool is being lowered therein. These pads 46 can be provided in addition to the hooks 42 and latch strip 45', or in place of the latter. When the latching device is used, the tool can be lowered through open hole below the casing shoe D for as far a distance as is desired before the reaming operation commences. If the latch is not provided, downward movement of the drill string B can be stopped when the bit passes out of the shoe D and the drill pipe B and bit A to allow the cutters 25 to produce the formation shoulder E under the influence of the compressed expander springs 3i. Drilling in a downward direction can then proceed as aforementioned, with the drill string B and mandrel H lowered against the action of the retractor spring 38 to position the lock portion 41 opposite the lugs 31 and prevent inward movement of the cutters until the drilling weight is removed from the drilling tool.

The lock portion 4'! of the tubular member preferably has flat faces 47a engaging corre sponding fiat faces Bid on the lugs 31 extending inwardly from the cutter supporting members 19. These fiat faces are preferred to provide a surface contact between the members and thus increase the load carrying capacity of the lock device, enabling it to resist to a greater extent the reactive force of the formation tending to press the cutters 25 inwardly from their expanded positions. The remaining portions of the tubular member 35, namely, the shoulder 39, the upper section 35a above the shoulder, and the portion which rides in the bearing guide'lll, are all circular in crodss-section to permit relative rotation, even to a slight extent, between the tubular member 35 and the kelly H within which it is received.

It is to be noted that relative rotation, at least to a slight extent, between the tubular member "and its locking portion 41 with respect to the driving kelly I4 is permitted, and this relative rotation is important, since it permits the lock portion 41 to adjust itself with respect to the lugs 31 on the cutter supports I9, and thus insure a surface contact therebetween, providing a large load-carrying capacity in the lock portion 41. If the tubular member 35' were incapable of swivelling or moving about the bit axis, line contact might result between the cutter lugs 31 and the lock portion 41 of the tubular member, producing concentrated wear on both of these parts during their resistance to the formation reactive forces, tending to press the cutters 25 inwardly from their retracted positions. Such wear would permit the cutters to shift inwardly and would result in the production of a reamed hole of lesser diameter than that desired.

As is pointed out in my above identified application, Serial No. 686,806, there is still a further advantage to the swivel or relatively oscillatable connection between the tubular lock member 35 and the driving Kelly M. Although the kelly is telescopically splined to the body IS, a slight amount of relative arcuate movement between them can occur because of the working clearances that must be maintained between the hexagonal kellyila, and hexagonal socket l5a in the body. The rigid attachment of the tubular lock member 35 to the kelly l4 would result in angular movement of the lock portion 41 with respect to the cutter supports 19 during the drilling operation, and would result in line contact between the lock portion 4'! and lugs 31, rather than the desirable surface contact. The swivel connection prevents the transmission of such relative angular movement of the kelly M with respect to the body iithrough the tubular member 35, since the latter is rotatable in the kelly and is unaffected by the turning movement of the latter; None of the drilling torque transmitted through the driving kelly M to the body l5 passes through the tubular member 35 and its locking portion 41 onto the supporting members l9.

To further ofier assurance that the locking portion 4'! and the lugs 31 will engage one another along a surface contact, the upper portion of the longitudinal groove 60 between the bifurcated arms 20, 20, extending completely transversely through the main body I5 of the tool, has parallel side walls Bl which make a slidable fit with the sides lea of the cutter supporting members 9. In addition, the lock portion 4 of the mandrel also has its opposed surfaces 416, at right angles to itslug contacting surfaces "a, parallel to one another and adapted to have slidable contact with the walls 6| of the transverse slot or groove 60.- v

, The provision of the slidable contact between the walls (if of the slot and the sides l9a of the cutter supporting member, on the one hand, and with the sides 41b of the lock portion 41 of the mandrel l f, on the: other hand, insures the aligmnent or registry of all the parts with respect to each other, and also insures the surface contact between the lock member 41 and the lugs 31 on the supporting members. sides SI of the longitudinal slot 60 can be machined accurately and parallel to one another, which is alsotrue of the sides lea of each cutter supporting member [9; Moreover, the surface 31a of the lug 31 of each supporting mem ber can be machined at right angles to the side The t surfaces 19a of the cutter supporting member,

and the side guiding surfaces 41b of the lock portion of the mandrel can be machined perpendicular to its lugengaging surfaces 41a. The distances between the parallel surfaces lea are made equal to the distance between the parallel surfaces 47?), and this dimension is only slightly less than the distance between the parallel slot walls iii, to allow proper working clearance between the several parts. The walls, however, serve to slidably guide the cutter. supporting members l9 and the lock 41 in their respective movements.

It becomes apparent that following assembly of the parts, the side walls of the slot 60 cooperate with the sides 41b of the lock portionto hold their lock surfaces 41a at right angles to the slot walls. Similarly, the sides 6| of the slot cooperate with the companion sides I911 of the cutter supporting members to insure that the lug surfaces 31d will be disposed at right angles to the walls 6! of the slot. Thisarrange ment insures that the lock surfaces 41a of the lock portion of the mandrel will be parallel to the companion surfaces 31a on the lugs 31 when the cutters 25 are in their'outwardlyexpanded position, which provides the desired surfal'c'econ tact therebetween.

It is to be noted that despite the guiding oi the lock portion 41' of the mandrel by the walls 6! of the slot during longitudinal movement of; the former, and the registering of the lock sur faces Ma by the walls of the slot with the companion surfaces 31a of the cutter supporting member lugs 37, the swivel connection is still provided between the kelly 14 and the tubular mandrel 35. This will prevent the'drilling torque from being transmitted through the locking device 41 to the cutter supporting members l9.

However, the working clearances 'thatstill must;

be provided between the lock portion 41 of the mandrel l l and the walls 5! of the slot still permit slight angular movement of the mandrel member 35 with respect to the main body iii of the bit and insures the adjustability of the lockand providing assurance against the reamingor drilling of an undersized well-bore. The relationships between the parts is such that their machining to proper dimensions and their.ap-' propriate assembly are comparatively simple'to' perform. I

Having thus described my invention, what I claim and desire to secure by Le ters Patent is: l. A rotary well drilling bit: including abody having atransverse slot therein: cutter means mounted on said body within said slot; means for expanding and holding said cutter means laterallyoutward, said expanding and holding means comprising ,a'first member connectable to a drill string and. movabler-in a longitudinaldirection along said body, a second member rotatably connected to said first member for longitudinal movement therewith and engageablewith said cutter means for holding-said cut-, v

ter means laterally outward; said cutter means and second member having guiding surfaces in slidable contacting relation to guiding surfaces provided by the walls of said slot.

2. A rotary well drilling bit: including a body having a transverse slot therein; cutter means mounted on said body within said slot for lateral movement with respect to said body; means for expanding and holding said cutter means laterally outward, said expanding and'holding means comprising instrumentalities connectable to a drill string and movable in a longitudinal direction along said body into engagement with said cutter means for holding said cutter means laterally outward; said cutter means and instrumentalities having guiding surfaces in slidable contacting relation to guiding surfaces provided by the opposed walls of said slot during lateral movement of said cutter means and longitudinal movement of said instrumentalities.

3. A rotary well drilling bit: including a body having opposed walls parallel to each other and defining a transverse slot therebetween; cutter means mounted on said body within said slot for lateral movement with respect to said body; means for expanding and holding said cutter means laterally outward, said expanding and holding means comprising instrumentalities connectable to a drill string and movable in a longitudinal direction along said body into engagement with said cutter means for holding said cutter means laterally outward; said cutter means and instrumentalities each having parallel' guiding surfaces in slidable contacting relation to said walls of said body during lateral movementof said cutter means and longitudinal movement of said instrumentalities.

4. A rotary well drilling bit: including a body having opposed walls parallel to each other and defining a transverse slot therebetween; cutter means mounted on said body within said slot; means for expanding and holding said cutter means laterally outward, said expanding and holding means comprising a first member connectable to a drillstring and movable in a longitudinal direction along said body, a second member rotatably connected to said first member for longitudinal movement therewith and engageable with said cutter means for holding said cutter means laterally outward; said cutter means and second member each having parallel guidingsurfaces in slidable contacting relation to said walls of said body.

. 5. A rotary Well drilling bit: including a body having opposed walls parallel to each other and defining a transverse slot therebetween; cutter means mounted on said body within said slot; means for expanding and holding said cutter means laterally outward, said expanding and holding means comprising a first member slidablysplined to said body and movable in a longitudinal direction along said body, a second member swivelly connected to said first member for. longitudinal movement therewith and engageable with said cutter means for holding said cutter means laterally outward; said cutter means and second member each having parallel guiding surfaces in slidable contacting relation to said walls of said body.

6. A rotary well drilling bit: including a body having opposed walls parallel to each other and defining a transverse slot therebetween; cutter means mounted on said body within said slot; elastic means engaging said cutter means for expanding said cutter means laterally outward; a lock device movable in one longitudinal direction along said body to a position preventing inward movement of said cutter means from its outwardly expanded position, said lock device comprising a first member splined to said body and a second member rotatable with respect to said first member and engageable with said cutter means, said second member being connected to said first member for longitudinal movement therewith; said cutter means and second member each having parallel guiding surfaces in slidable contacting relation to said walls of said body.

7. A rotary well drilling bit: including a body having opposed walls parallel to each other and defining a transverse slot therebetween; cutter means mounted on said body within said slot for lateral movement with respect to said body; elastic meansengaging said cutter means for expanding said cutter means laterally outward; a lock device movable in one longitudinal, direction along said body to a position preventing inward movement of said cutter means from its outwardly expanded position, said lock device comprising a first member connectible to a drill string and slidably splined to said body and a second member engageable with said cutter means; swivel means connecting said first and second members together for joint longitudinal movement and for angular movement with respect to each other; said cutter means and second member each having parallel surfaces in slidable contacting relation to said walls of said body during lateral movement of said cutter means and longitudinal movement of said members.

8. A rotary well drilling bit: including a body having opposed walls parallel to each other and defining a transverse slot therebetween; cutter means mounted on said body within said slot for lateral movement with respect to said body; means for expanding and holding said cutter means laterally outward, said expanding and holding means comprising a first member connectible to a drill string and slidably splined to said body, a second member engageable with said cutter means for holding said cutter means laterally outward, swivel means connecting said first and second members together for joint longitudinal movement and for angular movement with respect to each other; said cutter means and second member each having parallel surfaces in slidable contacting relation to said walls of said body during lateral movement of said cutter means and longitudinal movement of said members.

9. A rotary well drilling bit: including a body having a transverse slot therein; cutter means mounted on said body within said slot for lateral 'to each other; said cutter means and second member having non-cylindrical guiding surfaces in slidable contacting relation to guiding surfaces provided by the walls of said slot during lateral movement of said cutter means and lon- V gitudinal movement of said members.

10. A rotary well drilling bit: including a body; cutter means mounted on said body for lateral movement with respect to said body; means for expanding and holding said cutter means laterally outward, said expanding and holding means comprising a first member connectable to a drilling string and slidably splined to said body, a second member engageable with said cutter means along a surface of contact substantially normal to the direction of lateral movement of said cutter means relative to said body, means rotatably connecting said second member to said first member; said body and second member having surfaces in engagement with each other substantially parallel to the direction of lateral movement of said cutter means relative to said body to limit the extent of relative rotation between said second member and first member.

ARCHER W. KAMMERER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 449,613 Cameron Mar. 31, 1891 465,103 Wegner Dec. 15, 1891 789,929 North May 16, 1905 1,006,446 Delmore Oct. 17, 1911 1,031,628 Delmore July 2, 1912 1,133,481 Lego Mar. 30, 1915 1,179,284 Cox Apr. 11, 1916 1,183,630 Brys-on May 15, 1916 1,369,959 Booker Mar. 1, 1921 1,372,894 Minton Mar. 29, 1921 1,414,704 Newkirk May 2, 1922 1,678,075 Phipps July 24, 1928 1,834,335 Gram Dec. 1, 1931 

